Add logging to WebView zygote package preload.

This is a potentially slow event and having a timestamp for when it
started/completed may help to track down a currently-open bug (as well
as enable us to see how long preloading took). This only happens once
per boot and once per WebView update so won't cause a significant amount
of logging.

Bug: 37347817
Test: check for messages in logcat on first use of WebView
Change-Id: Ib6c50eea71324f81cda5b5b1ac91f9dc806e0ab4

1 files changed, 2 insertions, 0 deletions

diff --git a/core/java/com/android/internal/os/WebViewZygoteInit.java b/core/java/com/android/internal/os/WebViewZygoteInit.java
index cc3f58cb0c3d..e28079fd5cdd 100644
--- a/core/java/com/android/internal/os/WebViewZygoteInit.java
+++ b/core/java/com/android/internal/os/WebViewZygoteInit.java
@@ -70,6 +70,7 @@ class WebViewZygoteInit {
         @Override
         protected boolean handlePreloadPackage(String packagePath, String libsPath,
                                                String cacheKey) {
+            Log.i(TAG, "Beginning package preload");
             // Ask ApplicationLoaders to create and cache a classloader for the WebView APK so that
             // our children will reuse the same classloader instead of creating their own.
             // This enables us to preload Java and native code in the webview zygote process and
@@ -97,6 +98,7 @@ class WebViewZygoteInit {
                      IllegalAccessException | InvocationTargetException e) {
                 Log.e(TAG, "Exception while preloading package", e);
             }
+            Log.i(TAG, "Package preload done");
             return false;
         }
     }